http://acm.hdu.edu.cn/showproblem.php?pid=4403 题意: 给出一串数字,在里面添加一个等号和多个+号,使得等式成立,问有多少种不同的式子. 思路: 数据量比较小,直接dfs爆搜答案即可. #include<iostream> #include<cstdio> #include<cstring> #include<algorithm> #include<map> using namespace std;…

巨麻烦的模拟题orz.... 先确定等号的位置,然后两层dfs,分别算等号前面的和后面的,再比较 话说这题竟然不开long long都能水过 #include <iostream> #include<cstring> using namespace std; int ANS,ansx,ansy,T,l; string s; ],ny[],ax[],ay[],a[]; int lx,ly; int calcx() { //ax[1..lx-1] //nx[1..lx] ]; ; ;i…

思路:分等号左边和右边进行搜索 #include<iostream> #include<cstdio> #include<cstring> #include<cmath> #include<algorithm> #define LL __int64 using namespace std; ]; int n,ans; void right(LL sum,LL now,int cnt) { if(cnt==n) { if(sum==now) ans…

水水的dfs #include <cstdio> #include <cstring> #include <cstdlib> #include <cmath> #include <algorithm> using namespace std; char b[20]; int a[20], ans; void dfs(int cur, int len) { if(cur == len - 1) { a[cur] = 1; int d[2] = {}…

#include<cstdio> #include<cstring> #include<iostream> #include<cmath> #include<algorithm> #include<vector> using namespace std; ; ; const int INF = 0x3f3f3f; vector<int> l[maxn]; vector<int> r[maxn]; char s[…

A very hard Aoshu problem Problem Description Aoshu is very popular among primary school students. It is mathematics, but much harder than ordinary mathematics for primary school students. Teacher Liu is an Aoshu teacher. He just comes out with a pro…

暴力$dfs$. 先看数据范围,字符串最长只有$15$,也就是说枚举每个字符后面是否放置“$+$”号的复杂度为${2^{15}}$. 每次枚举到一种情况,看哪些位置能放“$=$”号,每个位置都试一下,然后判断一下是否可行. 最坏复杂度$O({2^{15}}*{15^2})$,事实上是达不到最坏复杂度的. #pragma comment(linker, "/STACK:1024000000,1024000000") #include<cstdio> #include<c…

题意:给一串数字,在其间加入若干加号和一个等号,问使等式成立的方案总数 if the digits serial is "1212", you can get 2 equations, they are "12=12" and "1+2=1+2". 一看就是搜索,但是不太好写,还是参考了kuang神和这里 的大神写的 先枚举左边的所有和的情况,然后判断右边是否存在相等的情况 #include<cstdio> #include<i…

题意:给你一个数字字符串.问在字符串中间加'='.'+'使得'='左右两边相等. 1212  : 1+2=1+2,   12=12. 12345666 : 12+3+45+6=66.  1+2+3+4+56=66: #include<stdio.h> #include<string.h> #include<string> #include<map> #include<stack> #include<math.h> #include&l…

比赛链接: http://vjudge.net/contest/view.action?cid=47642#overview 题目来源: 2012 ACM/ICPC Asia Regional Jinhua Online     ID Origin Title   18 / 70 Problem A HDU 4400 Mines  (搜索, ★★★☆☆)   1 / 1 Problem B HDU 4401 Battery (数学, ★★☆☆☆ )    2 / 2 Problem C HDU…